1、Designation: A288 91 (Reapproved 2018)Standard Specification forCarbon and Alloy Steel Forgings for Magnetic RetainingRings for Turbine Generators1This standard is issued under the fixed designation A288; the number immediately following the designation indicates the year oforiginal adoption or, in
2、the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers quenched and tempered carbonand alloy steel forgings for m
3、agnetic retaining rings for turbinegenerators.1.2 Supplementary requirements of an optional nature areprovided. These shall apply only when specified by thepurchaser.1.3 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions t
4、o SI units that are provided for information onlyand are not considered standard.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides
5、 and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2A275/A275M Practice for Magnetic Particle Examination ofSteel ForgingsA531/A531M Practice for Ultrasonic Examination ofTurbine-Generator Steel Retaining
6、RingsA788/A788M Specification for Steel Forgings, General Re-quirements3. Ordering Information3.1 In addition to the ordering information required bySpecification A788/A788M, the purchaser shall include withthe inquiry and order a detailed drawing, sketch, or writtendescription of the forging, inclu
7、ding the number and locationof mechanical test specimens.4. Manufacture4.1 The melting processes of Specification A788/A788Mshall be applicable except that the basic electric furnaceprocess shall be used if separate refining or remelting is notemployed.4.2 Vacuum DegassingFor Class 3 machined forgin
8、gsover 212 in. (63.5 mm) wall thickness, and Classes 4 to 8, themolten steel shall be vacuum treated immediately prior to orduring the operation of pouring the ingot in order to removeobjectionable gases, especially hydrogen.4.3 DiscardSufficient discard shall be made from eachingot to secure freedo
9、m from piping and undue segregation.4.4 Heat Treatment:4.4.1 Heat Treatment for Mechanical PropertiesHeattreatment for properties shall be by quenching and tempering.4.4.2 Tempering TemperatureThe final tempering tem-perature shall be not less than 1100 F (595 C).4.5 Machining:4.5.1 Preliminary Mach
10、iningForgings shall be machinedall over prior to quenching and tempering for mechanicalproperties.4.5.2 Machine to Purchasers Requirements forShipmentIf required, forgings shall be machined to thedimensions shown on the purchasers drawing prior to ship-ment.5. Chemical Composition5.1 The steel shall
11、 conform to the chemical compositionprescribed in Table 1.5.2 Heat AnalysisThe heat analysis obtained from sam-pling in accordance with Specification A788/A788M shallcomply with Table 1.5.3 Product AnalysisThe purchaser may use the productanalysis provision of Table 1 of Specification A788/A788M too
12、btain a product analysis from a forging representing each heator multiple heat.1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved
13、 March 1, 2018. Published March 2018. Originallyapproved in 1946. Last previous edition approved in 2013 as A288 91(2013).DOI: 10.1520/A0288-91R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandard
14、s volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on
15、 standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.16. Mechanical Properties6.1 Tensile RequirementsThe material shall conform tothe re
16、quirements for tensile properties prescribed in Table 2.6.2 Notch Toughness RequirementsThe material shallconform to the requirements for notch toughness as prescribedin Table 2.7. General Requirements7.1 Material supplied to this specification shall conform tothe requirements of Specification A788/
17、A788M which outlinesadditional ordering information, manufacturing, requirements,testing and retesting methods, and procedures, marking,certification, product analysis variations, and additional supple-mentary requirements.7.2 If the requirements of this specification are in conflictwith the require
18、ments of Specification A788/A788M, therequirements of this specification shall prevail.8. Sampling8.1 Test LocationTension and notch toughness test speci-mens shall be taken tangentially from prolongations on one orboth ends of the forging. The direction of the notch of theCharpy bars shall be radia
19、l. All test specimens shall be locatedat midwall and at a distance at least equal to one-half the wallthickness from the end face of the prolongation.8.2 RemovalAll tension and notch toughness test speci-mens shall be removed after final heat treatment.9. Number of Tests and Retests9.1 Number of Tes
20、tsThe number of tension and notchtoughness test specimens shall be as prescribed by thepurchaser, but in no case shall there be less than one tensionand one notch toughness test specimen for each ring.9.2 If any test specimen fails to meet the requirementsspecified, two adjacent test specimens may b
21、e selected forretest without reheat-treatment if the failure was not caused byruptures, cracks, or flakes in the steel. Both of these must meetthe requirements of this specification.9.3 If the results of the mechanical tests of any forging donot conform to the requirements specified, the manufacture
22、rmay reaustenitize the forging, but not more than once withoutapproval of the purchaser. Forgings may be retempered withoutobtaining approval of the purchaser.10. Test Methods10.1 Nondestructive Tests:10.1.1 General RequirementsThe ring shall be free fromcracks, seams, laps, shrinkage, and other inj
23、urious imperfec-tions.10.1.2 Magnetic Particle TestMagnetic particle tests of allsurfaces shall be made at the manufacturers plant. Theprocedure for tests shall be in accordance with PracticeA275/A275M. The standards of acceptance shall be by agree-ment between purchasers and manufacturers.10.1.3 Ul
24、trasonic InspectionAn ultrasonic inspectionshall be made at the manufacturers plant on the machined ringin accordance with Practice A531/A531M. The standards ofacceptance shall be by agreement between purchaser andmanufacturer.ASTM International takes no position respecting the validity of any paten
25、t rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision a
26、t any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your commen
27、ts will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted
28、by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mai
29、l); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Chemical RequirementsClass 1, % Classes 2and 3, %Classes 4, 5, 6, 7,and 8, %Carbon,
30、max 0.50 max 0.45 max 0.45Manganese 0.601.00 0.601.00 1.00 maxPhosphorus, max 0.025 0.025 0.025Sulfur, max 0.025 0.020 0.020Silicon 0.150.30 0.150.35 0.150.35Nickel . . .A1.653.50Chromium . . . 0.701.25 0.701.25Molybdenum . . . 0.15 min 0.20 minVanadium . . . optional 0.070.12AFor Class 3 rings with
31、 wall thickness over 212 in. (63.5 mm) drawing size, thenickel content shall be 0.852.0 %.TABLE 2 Tensile and Notch Toughness RequirementsClass TensileStrengthmin, psi(MPa)Yield Strength(0.02 %, offset),min, psi (MPa)Elonga-tionin2in.or50mm,min, %Reduc-tion ofArea,min,%CharpyV-notchImpactStrength,Ro
32、omTempera-ture min,ft-lbf (J)1 70 000 (485) 45 000 (310) 18 40 15 (20)2 90 000 (620) 65 000 (450) 20 50 25 (34)3 110 000 (760) 80 000 (550) 18 50 20 (27)4 120 000 (825) 95 000 (655) 18 45 35 (47)5 130 000 (895) 110 000 (760) 16 40 30 (41)6 140 000 (965) 125 000 (860) 14 40 30 (41)7 150 000 (1035) 135 000 (930) 13 35 25 (34)8 165 000 (1140) 150 000 (1035) 12 35 25 (34)A288 91 (2018)2
